1. Field of the Invention
The present invention generally relates to manifolds which permit the rotation of one end of the manifold with respect to the other without an interruption of flow therethrough. The present invention specifically relates to multiple path fluid manifolds for the transport of seabed well fluids to a floating production, storage and off-loading (FPSO) vessel.
2. Discussion of the Prior Art
An exposed location FPSO vessel must be able to weathervane on its mooring as the wind direction changes. In the past, multiple path fluid swivels have been employed at the interface between the riser conduit from the seabed well and the vessel in order to permit weathervaning. Such a multi-path swivel can be seen in Gentry et al, U.S. Pat. No. 4,436,048 issued Mar. 13, 1984, herein incorporated by reference. The multi-path swivel assembly 120 is shown generally in FIG. 11 and in more detail in FIGS. 13-16 and discussed between column 14, line 65 and column 15, line 53. Although the conventional multi-path fluid swivel illustrated in the patent is a solution to the weathervaning problem, pressure limitations on the swivel seals prevent the application or use on FPSO vessels in some oil fields. Where pressures above about 2000 psi are encountered, a non-swivel seal such as that in Gentry et al should be used instead. However, if any substantial amount of weathervaning occurred, the FPSO vessel would have to be disconnected from the riser and then reconnected after the desired weathervaning movement had occurred.